Maria skrev den 2019-02-07 11:55:

A few days ago I setup my Roundcube email on my iPhone,

no apple do not provide you with roundcubes

since then I receive all emails on my iPhone

good ?

but only some of them appear on my Inbox folder when I open my email on my laptop!

you see the sign of READ some mails on iphone ?

roundcube can based on that hide emails already READed :=)

hopefully you did not setup iphone with pop3 :(

Does someone have an idea why this might be happening and how I can fix it?

there is nothing to fix